Sensitivity of Double-Negative Metamaterial Optical Sensor

Optical sensors have wide range of application such as in medicine, astronomy, industry, and others. Sensitivity of symmetric three layered optical waveguide sensor is investigated. The proposed sensor consists of dielectric slab surrounded by metamaterial (MTM) cladding and MTM substrate. MTMs are new artificial materials which have simultaneously negative permittivity ε and negative permeability μ. Different values of MTMs parameters ε and μ are chosen to optimize the sensitivity of the sensor. However, the value of εμ is kept content and equal to 4. The dispersion equation which represents the effective index ne for transverse electric modes (TE) as a function of slab thickness has been derived. A close form solution of the sensitivity (S) which is defined as the variation of the effective index with respect to Temperature variation is introduced. The sensitivity then numerically calculated as function of the film thickness at different values of Metamaterial parameters. It is found that sensitivity varies with the film thickness and depends on the MTMs parameters. These results are important for designing sensors.